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1da177e4 LT |
1 | /* |
2 | * linux/kernel/sys.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
1da177e4 LT |
7 | #include <linux/module.h> |
8 | #include <linux/mm.h> | |
9 | #include <linux/utsname.h> | |
10 | #include <linux/mman.h> | |
11 | #include <linux/smp_lock.h> | |
12 | #include <linux/notifier.h> | |
13 | #include <linux/reboot.h> | |
14 | #include <linux/prctl.h> | |
1da177e4 LT |
15 | #include <linux/highuid.h> |
16 | #include <linux/fs.h> | |
3e88c553 | 17 | #include <linux/resource.h> |
dc009d92 EB |
18 | #include <linux/kernel.h> |
19 | #include <linux/kexec.h> | |
1da177e4 | 20 | #include <linux/workqueue.h> |
c59ede7b | 21 | #include <linux/capability.h> |
1da177e4 LT |
22 | #include <linux/device.h> |
23 | #include <linux/key.h> | |
24 | #include <linux/times.h> | |
25 | #include <linux/posix-timers.h> | |
26 | #include <linux/security.h> | |
27 | #include <linux/dcookies.h> | |
28 | #include <linux/suspend.h> | |
29 | #include <linux/tty.h> | |
7ed20e1a | 30 | #include <linux/signal.h> |
9f46080c | 31 | #include <linux/cn_proc.h> |
3cfc348b | 32 | #include <linux/getcpu.h> |
6eaeeaba | 33 | #include <linux/task_io_accounting_ops.h> |
1d9d02fe | 34 | #include <linux/seccomp.h> |
1da177e4 LT |
35 | |
36 | #include <linux/compat.h> | |
37 | #include <linux/syscalls.h> | |
00d7c05a | 38 | #include <linux/kprobes.h> |
acce292c | 39 | #include <linux/user_namespace.h> |
1da177e4 LT |
40 | |
41 | #include <asm/uaccess.h> | |
42 | #include <asm/io.h> | |
43 | #include <asm/unistd.h> | |
44 | ||
45 | #ifndef SET_UNALIGN_CTL | |
46 | # define SET_UNALIGN_CTL(a,b) (-EINVAL) | |
47 | #endif | |
48 | #ifndef GET_UNALIGN_CTL | |
49 | # define GET_UNALIGN_CTL(a,b) (-EINVAL) | |
50 | #endif | |
51 | #ifndef SET_FPEMU_CTL | |
52 | # define SET_FPEMU_CTL(a,b) (-EINVAL) | |
53 | #endif | |
54 | #ifndef GET_FPEMU_CTL | |
55 | # define GET_FPEMU_CTL(a,b) (-EINVAL) | |
56 | #endif | |
57 | #ifndef SET_FPEXC_CTL | |
58 | # define SET_FPEXC_CTL(a,b) (-EINVAL) | |
59 | #endif | |
60 | #ifndef GET_FPEXC_CTL | |
61 | # define GET_FPEXC_CTL(a,b) (-EINVAL) | |
62 | #endif | |
651d765d AB |
63 | #ifndef GET_ENDIAN |
64 | # define GET_ENDIAN(a,b) (-EINVAL) | |
65 | #endif | |
66 | #ifndef SET_ENDIAN | |
67 | # define SET_ENDIAN(a,b) (-EINVAL) | |
68 | #endif | |
1da177e4 LT |
69 | |
70 | /* | |
71 | * this is where the system-wide overflow UID and GID are defined, for | |
72 | * architectures that now have 32-bit UID/GID but didn't in the past | |
73 | */ | |
74 | ||
75 | int overflowuid = DEFAULT_OVERFLOWUID; | |
76 | int overflowgid = DEFAULT_OVERFLOWGID; | |
77 | ||
78 | #ifdef CONFIG_UID16 | |
79 | EXPORT_SYMBOL(overflowuid); | |
80 | EXPORT_SYMBOL(overflowgid); | |
81 | #endif | |
82 | ||
83 | /* | |
84 | * the same as above, but for filesystems which can only store a 16-bit | |
85 | * UID and GID. as such, this is needed on all architectures | |
86 | */ | |
87 | ||
88 | int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; | |
89 | int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; | |
90 | ||
91 | EXPORT_SYMBOL(fs_overflowuid); | |
92 | EXPORT_SYMBOL(fs_overflowgid); | |
93 | ||
94 | /* | |
95 | * this indicates whether you can reboot with ctrl-alt-del: the default is yes | |
96 | */ | |
97 | ||
98 | int C_A_D = 1; | |
9ec52099 CLG |
99 | struct pid *cad_pid; |
100 | EXPORT_SYMBOL(cad_pid); | |
1da177e4 LT |
101 | |
102 | /* | |
103 | * Notifier list for kernel code which wants to be called | |
104 | * at shutdown. This is used to stop any idling DMA operations | |
105 | * and the like. | |
106 | */ | |
107 | ||
e041c683 AS |
108 | static BLOCKING_NOTIFIER_HEAD(reboot_notifier_list); |
109 | ||
110 | /* | |
111 | * Notifier chain core routines. The exported routines below | |
112 | * are layered on top of these, with appropriate locking added. | |
113 | */ | |
114 | ||
115 | static int notifier_chain_register(struct notifier_block **nl, | |
116 | struct notifier_block *n) | |
117 | { | |
118 | while ((*nl) != NULL) { | |
119 | if (n->priority > (*nl)->priority) | |
120 | break; | |
121 | nl = &((*nl)->next); | |
122 | } | |
123 | n->next = *nl; | |
124 | rcu_assign_pointer(*nl, n); | |
125 | return 0; | |
126 | } | |
127 | ||
128 | static int notifier_chain_unregister(struct notifier_block **nl, | |
129 | struct notifier_block *n) | |
130 | { | |
131 | while ((*nl) != NULL) { | |
132 | if ((*nl) == n) { | |
133 | rcu_assign_pointer(*nl, n->next); | |
134 | return 0; | |
135 | } | |
136 | nl = &((*nl)->next); | |
137 | } | |
138 | return -ENOENT; | |
139 | } | |
140 | ||
6f7cc11a GS |
141 | /** |
142 | * notifier_call_chain - Informs the registered notifiers about an event. | |
143 | * @nl: Pointer to head of the blocking notifier chain | |
144 | * @val: Value passed unmodified to notifier function | |
145 | * @v: Pointer passed unmodified to notifier function | |
146 | * @nr_to_call: Number of notifier functions to be called. Don't care | |
147 | * value of this parameter is -1. | |
148 | * @nr_calls: Records the number of notifications sent. Don't care | |
149 | * value of this field is NULL. | |
150 | * @returns: notifier_call_chain returns the value returned by the | |
151 | * last notifier function called. | |
152 | */ | |
153 | ||
e041c683 | 154 | static int __kprobes notifier_call_chain(struct notifier_block **nl, |
6f7cc11a GS |
155 | unsigned long val, void *v, |
156 | int nr_to_call, int *nr_calls) | |
e041c683 AS |
157 | { |
158 | int ret = NOTIFY_DONE; | |
bbb1747d | 159 | struct notifier_block *nb, *next_nb; |
e041c683 AS |
160 | |
161 | nb = rcu_dereference(*nl); | |
6f7cc11a GS |
162 | |
163 | while (nb && nr_to_call) { | |
bbb1747d | 164 | next_nb = rcu_dereference(nb->next); |
e041c683 | 165 | ret = nb->notifier_call(nb, val, v); |
6f7cc11a GS |
166 | |
167 | if (nr_calls) | |
168 | (*nr_calls)++; | |
169 | ||
e041c683 AS |
170 | if ((ret & NOTIFY_STOP_MASK) == NOTIFY_STOP_MASK) |
171 | break; | |
bbb1747d | 172 | nb = next_nb; |
6f7cc11a | 173 | nr_to_call--; |
e041c683 AS |
174 | } |
175 | return ret; | |
176 | } | |
177 | ||
178 | /* | |
179 | * Atomic notifier chain routines. Registration and unregistration | |
eabc0694 | 180 | * use a spinlock, and call_chain is synchronized by RCU (no locks). |
e041c683 | 181 | */ |
1da177e4 LT |
182 | |
183 | /** | |
e041c683 AS |
184 | * atomic_notifier_chain_register - Add notifier to an atomic notifier chain |
185 | * @nh: Pointer to head of the atomic notifier chain | |
1da177e4 LT |
186 | * @n: New entry in notifier chain |
187 | * | |
e041c683 | 188 | * Adds a notifier to an atomic notifier chain. |
1da177e4 LT |
189 | * |
190 | * Currently always returns zero. | |
191 | */ | |
e041c683 AS |
192 | |
193 | int atomic_notifier_chain_register(struct atomic_notifier_head *nh, | |
194 | struct notifier_block *n) | |
195 | { | |
196 | unsigned long flags; | |
197 | int ret; | |
198 | ||
199 | spin_lock_irqsave(&nh->lock, flags); | |
200 | ret = notifier_chain_register(&nh->head, n); | |
201 | spin_unlock_irqrestore(&nh->lock, flags); | |
202 | return ret; | |
203 | } | |
204 | ||
205 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_register); | |
206 | ||
207 | /** | |
208 | * atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain | |
209 | * @nh: Pointer to head of the atomic notifier chain | |
210 | * @n: Entry to remove from notifier chain | |
211 | * | |
212 | * Removes a notifier from an atomic notifier chain. | |
213 | * | |
214 | * Returns zero on success or %-ENOENT on failure. | |
215 | */ | |
216 | int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, | |
217 | struct notifier_block *n) | |
218 | { | |
219 | unsigned long flags; | |
220 | int ret; | |
221 | ||
222 | spin_lock_irqsave(&nh->lock, flags); | |
223 | ret = notifier_chain_unregister(&nh->head, n); | |
224 | spin_unlock_irqrestore(&nh->lock, flags); | |
225 | synchronize_rcu(); | |
226 | return ret; | |
227 | } | |
228 | ||
229 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); | |
230 | ||
231 | /** | |
6f7cc11a | 232 | * __atomic_notifier_call_chain - Call functions in an atomic notifier chain |
e041c683 AS |
233 | * @nh: Pointer to head of the atomic notifier chain |
234 | * @val: Value passed unmodified to notifier function | |
235 | * @v: Pointer passed unmodified to notifier function | |
6f7cc11a GS |
236 | * @nr_to_call: See the comment for notifier_call_chain. |
237 | * @nr_calls: See the comment for notifier_call_chain. | |
e041c683 AS |
238 | * |
239 | * Calls each function in a notifier chain in turn. The functions | |
240 | * run in an atomic context, so they must not block. | |
241 | * This routine uses RCU to synchronize with changes to the chain. | |
242 | * | |
243 | * If the return value of the notifier can be and'ed | |
72fd4a35 | 244 | * with %NOTIFY_STOP_MASK then atomic_notifier_call_chain() |
e041c683 AS |
245 | * will return immediately, with the return value of |
246 | * the notifier function which halted execution. | |
247 | * Otherwise the return value is the return value | |
248 | * of the last notifier function called. | |
249 | */ | |
1da177e4 | 250 | |
6f7cc11a GS |
251 | int __kprobes __atomic_notifier_call_chain(struct atomic_notifier_head *nh, |
252 | unsigned long val, void *v, | |
253 | int nr_to_call, int *nr_calls) | |
1da177e4 | 254 | { |
e041c683 AS |
255 | int ret; |
256 | ||
257 | rcu_read_lock(); | |
6f7cc11a | 258 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); |
e041c683 AS |
259 | rcu_read_unlock(); |
260 | return ret; | |
1da177e4 LT |
261 | } |
262 | ||
6f7cc11a GS |
263 | EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain); |
264 | ||
265 | int __kprobes atomic_notifier_call_chain(struct atomic_notifier_head *nh, | |
266 | unsigned long val, void *v) | |
267 | { | |
268 | return __atomic_notifier_call_chain(nh, val, v, -1, NULL); | |
269 | } | |
e041c683 | 270 | |
6f7cc11a | 271 | EXPORT_SYMBOL_GPL(atomic_notifier_call_chain); |
e041c683 AS |
272 | /* |
273 | * Blocking notifier chain routines. All access to the chain is | |
274 | * synchronized by an rwsem. | |
275 | */ | |
1da177e4 LT |
276 | |
277 | /** | |
e041c683 AS |
278 | * blocking_notifier_chain_register - Add notifier to a blocking notifier chain |
279 | * @nh: Pointer to head of the blocking notifier chain | |
1da177e4 LT |
280 | * @n: New entry in notifier chain |
281 | * | |
e041c683 AS |
282 | * Adds a notifier to a blocking notifier chain. |
283 | * Must be called in process context. | |
1da177e4 | 284 | * |
e041c683 | 285 | * Currently always returns zero. |
1da177e4 LT |
286 | */ |
287 | ||
e041c683 AS |
288 | int blocking_notifier_chain_register(struct blocking_notifier_head *nh, |
289 | struct notifier_block *n) | |
1da177e4 | 290 | { |
e041c683 AS |
291 | int ret; |
292 | ||
293 | /* | |
294 | * This code gets used during boot-up, when task switching is | |
295 | * not yet working and interrupts must remain disabled. At | |
296 | * such times we must not call down_write(). | |
297 | */ | |
298 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
299 | return notifier_chain_register(&nh->head, n); | |
300 | ||
301 | down_write(&nh->rwsem); | |
302 | ret = notifier_chain_register(&nh->head, n); | |
303 | up_write(&nh->rwsem); | |
304 | return ret; | |
1da177e4 LT |
305 | } |
306 | ||
e041c683 | 307 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_register); |
1da177e4 LT |
308 | |
309 | /** | |
e041c683 AS |
310 | * blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain |
311 | * @nh: Pointer to head of the blocking notifier chain | |
312 | * @n: Entry to remove from notifier chain | |
313 | * | |
314 | * Removes a notifier from a blocking notifier chain. | |
315 | * Must be called from process context. | |
316 | * | |
317 | * Returns zero on success or %-ENOENT on failure. | |
318 | */ | |
319 | int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh, | |
320 | struct notifier_block *n) | |
321 | { | |
322 | int ret; | |
323 | ||
324 | /* | |
325 | * This code gets used during boot-up, when task switching is | |
326 | * not yet working and interrupts must remain disabled. At | |
327 | * such times we must not call down_write(). | |
328 | */ | |
329 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
330 | return notifier_chain_unregister(&nh->head, n); | |
331 | ||
332 | down_write(&nh->rwsem); | |
333 | ret = notifier_chain_unregister(&nh->head, n); | |
334 | up_write(&nh->rwsem); | |
335 | return ret; | |
336 | } | |
337 | ||
338 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister); | |
339 | ||
340 | /** | |
6f7cc11a | 341 | * __blocking_notifier_call_chain - Call functions in a blocking notifier chain |
e041c683 | 342 | * @nh: Pointer to head of the blocking notifier chain |
1da177e4 LT |
343 | * @val: Value passed unmodified to notifier function |
344 | * @v: Pointer passed unmodified to notifier function | |
6f7cc11a GS |
345 | * @nr_to_call: See comment for notifier_call_chain. |
346 | * @nr_calls: See comment for notifier_call_chain. | |
1da177e4 | 347 | * |
e041c683 AS |
348 | * Calls each function in a notifier chain in turn. The functions |
349 | * run in a process context, so they are allowed to block. | |
1da177e4 | 350 | * |
e041c683 | 351 | * If the return value of the notifier can be and'ed |
72fd4a35 | 352 | * with %NOTIFY_STOP_MASK then blocking_notifier_call_chain() |
1da177e4 LT |
353 | * will return immediately, with the return value of |
354 | * the notifier function which halted execution. | |
e041c683 | 355 | * Otherwise the return value is the return value |
1da177e4 LT |
356 | * of the last notifier function called. |
357 | */ | |
358 | ||
6f7cc11a GS |
359 | int __blocking_notifier_call_chain(struct blocking_notifier_head *nh, |
360 | unsigned long val, void *v, | |
361 | int nr_to_call, int *nr_calls) | |
1da177e4 | 362 | { |
1b5180b6 | 363 | int ret = NOTIFY_DONE; |
e041c683 | 364 | |
1b5180b6 IM |
365 | /* |
366 | * We check the head outside the lock, but if this access is | |
367 | * racy then it does not matter what the result of the test | |
368 | * is, we re-check the list after having taken the lock anyway: | |
369 | */ | |
370 | if (rcu_dereference(nh->head)) { | |
371 | down_read(&nh->rwsem); | |
6f7cc11a GS |
372 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, |
373 | nr_calls); | |
1b5180b6 IM |
374 | up_read(&nh->rwsem); |
375 | } | |
1da177e4 LT |
376 | return ret; |
377 | } | |
6f7cc11a | 378 | EXPORT_SYMBOL_GPL(__blocking_notifier_call_chain); |
1da177e4 | 379 | |
6f7cc11a GS |
380 | int blocking_notifier_call_chain(struct blocking_notifier_head *nh, |
381 | unsigned long val, void *v) | |
382 | { | |
383 | return __blocking_notifier_call_chain(nh, val, v, -1, NULL); | |
384 | } | |
e041c683 AS |
385 | EXPORT_SYMBOL_GPL(blocking_notifier_call_chain); |
386 | ||
387 | /* | |
388 | * Raw notifier chain routines. There is no protection; | |
389 | * the caller must provide it. Use at your own risk! | |
390 | */ | |
391 | ||
392 | /** | |
393 | * raw_notifier_chain_register - Add notifier to a raw notifier chain | |
394 | * @nh: Pointer to head of the raw notifier chain | |
395 | * @n: New entry in notifier chain | |
396 | * | |
397 | * Adds a notifier to a raw notifier chain. | |
398 | * All locking must be provided by the caller. | |
399 | * | |
400 | * Currently always returns zero. | |
401 | */ | |
402 | ||
403 | int raw_notifier_chain_register(struct raw_notifier_head *nh, | |
404 | struct notifier_block *n) | |
405 | { | |
406 | return notifier_chain_register(&nh->head, n); | |
407 | } | |
408 | ||
409 | EXPORT_SYMBOL_GPL(raw_notifier_chain_register); | |
410 | ||
411 | /** | |
412 | * raw_notifier_chain_unregister - Remove notifier from a raw notifier chain | |
413 | * @nh: Pointer to head of the raw notifier chain | |
414 | * @n: Entry to remove from notifier chain | |
415 | * | |
416 | * Removes a notifier from a raw notifier chain. | |
417 | * All locking must be provided by the caller. | |
418 | * | |
419 | * Returns zero on success or %-ENOENT on failure. | |
420 | */ | |
421 | int raw_notifier_chain_unregister(struct raw_notifier_head *nh, | |
422 | struct notifier_block *n) | |
423 | { | |
424 | return notifier_chain_unregister(&nh->head, n); | |
425 | } | |
426 | ||
427 | EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister); | |
428 | ||
429 | /** | |
6f7cc11a | 430 | * __raw_notifier_call_chain - Call functions in a raw notifier chain |
e041c683 AS |
431 | * @nh: Pointer to head of the raw notifier chain |
432 | * @val: Value passed unmodified to notifier function | |
433 | * @v: Pointer passed unmodified to notifier function | |
6f7cc11a GS |
434 | * @nr_to_call: See comment for notifier_call_chain. |
435 | * @nr_calls: See comment for notifier_call_chain | |
e041c683 AS |
436 | * |
437 | * Calls each function in a notifier chain in turn. The functions | |
438 | * run in an undefined context. | |
439 | * All locking must be provided by the caller. | |
440 | * | |
441 | * If the return value of the notifier can be and'ed | |
72fd4a35 | 442 | * with %NOTIFY_STOP_MASK then raw_notifier_call_chain() |
e041c683 AS |
443 | * will return immediately, with the return value of |
444 | * the notifier function which halted execution. | |
445 | * Otherwise the return value is the return value | |
446 | * of the last notifier function called. | |
447 | */ | |
448 | ||
6f7cc11a GS |
449 | int __raw_notifier_call_chain(struct raw_notifier_head *nh, |
450 | unsigned long val, void *v, | |
451 | int nr_to_call, int *nr_calls) | |
452 | { | |
453 | return notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
454 | } | |
455 | ||
456 | EXPORT_SYMBOL_GPL(__raw_notifier_call_chain); | |
457 | ||
e041c683 AS |
458 | int raw_notifier_call_chain(struct raw_notifier_head *nh, |
459 | unsigned long val, void *v) | |
460 | { | |
6f7cc11a | 461 | return __raw_notifier_call_chain(nh, val, v, -1, NULL); |
e041c683 AS |
462 | } |
463 | ||
464 | EXPORT_SYMBOL_GPL(raw_notifier_call_chain); | |
1da177e4 | 465 | |
eabc0694 AS |
466 | /* |
467 | * SRCU notifier chain routines. Registration and unregistration | |
468 | * use a mutex, and call_chain is synchronized by SRCU (no locks). | |
469 | */ | |
470 | ||
471 | /** | |
472 | * srcu_notifier_chain_register - Add notifier to an SRCU notifier chain | |
473 | * @nh: Pointer to head of the SRCU notifier chain | |
474 | * @n: New entry in notifier chain | |
475 | * | |
476 | * Adds a notifier to an SRCU notifier chain. | |
477 | * Must be called in process context. | |
478 | * | |
479 | * Currently always returns zero. | |
480 | */ | |
481 | ||
482 | int srcu_notifier_chain_register(struct srcu_notifier_head *nh, | |
483 | struct notifier_block *n) | |
484 | { | |
485 | int ret; | |
486 | ||
487 | /* | |
488 | * This code gets used during boot-up, when task switching is | |
489 | * not yet working and interrupts must remain disabled. At | |
490 | * such times we must not call mutex_lock(). | |
491 | */ | |
492 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
493 | return notifier_chain_register(&nh->head, n); | |
494 | ||
495 | mutex_lock(&nh->mutex); | |
496 | ret = notifier_chain_register(&nh->head, n); | |
497 | mutex_unlock(&nh->mutex); | |
498 | return ret; | |
499 | } | |
500 | ||
501 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_register); | |
502 | ||
503 | /** | |
504 | * srcu_notifier_chain_unregister - Remove notifier from an SRCU notifier chain | |
505 | * @nh: Pointer to head of the SRCU notifier chain | |
506 | * @n: Entry to remove from notifier chain | |
507 | * | |
508 | * Removes a notifier from an SRCU notifier chain. | |
509 | * Must be called from process context. | |
510 | * | |
511 | * Returns zero on success or %-ENOENT on failure. | |
512 | */ | |
513 | int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh, | |
514 | struct notifier_block *n) | |
515 | { | |
516 | int ret; | |
517 | ||
518 | /* | |
519 | * This code gets used during boot-up, when task switching is | |
520 | * not yet working and interrupts must remain disabled. At | |
521 | * such times we must not call mutex_lock(). | |
522 | */ | |
523 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
524 | return notifier_chain_unregister(&nh->head, n); | |
525 | ||
526 | mutex_lock(&nh->mutex); | |
527 | ret = notifier_chain_unregister(&nh->head, n); | |
528 | mutex_unlock(&nh->mutex); | |
529 | synchronize_srcu(&nh->srcu); | |
530 | return ret; | |
531 | } | |
532 | ||
533 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister); | |
534 | ||
535 | /** | |
6f7cc11a | 536 | * __srcu_notifier_call_chain - Call functions in an SRCU notifier chain |
eabc0694 AS |
537 | * @nh: Pointer to head of the SRCU notifier chain |
538 | * @val: Value passed unmodified to notifier function | |
539 | * @v: Pointer passed unmodified to notifier function | |
6f7cc11a GS |
540 | * @nr_to_call: See comment for notifier_call_chain. |
541 | * @nr_calls: See comment for notifier_call_chain | |
eabc0694 AS |
542 | * |
543 | * Calls each function in a notifier chain in turn. The functions | |
544 | * run in a process context, so they are allowed to block. | |
545 | * | |
546 | * If the return value of the notifier can be and'ed | |
72fd4a35 | 547 | * with %NOTIFY_STOP_MASK then srcu_notifier_call_chain() |
eabc0694 AS |
548 | * will return immediately, with the return value of |
549 | * the notifier function which halted execution. | |
550 | * Otherwise the return value is the return value | |
551 | * of the last notifier function called. | |
552 | */ | |
553 | ||
6f7cc11a GS |
554 | int __srcu_notifier_call_chain(struct srcu_notifier_head *nh, |
555 | unsigned long val, void *v, | |
556 | int nr_to_call, int *nr_calls) | |
eabc0694 AS |
557 | { |
558 | int ret; | |
559 | int idx; | |
560 | ||
561 | idx = srcu_read_lock(&nh->srcu); | |
6f7cc11a | 562 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); |
eabc0694 AS |
563 | srcu_read_unlock(&nh->srcu, idx); |
564 | return ret; | |
565 | } | |
6f7cc11a | 566 | EXPORT_SYMBOL_GPL(__srcu_notifier_call_chain); |
eabc0694 | 567 | |
6f7cc11a GS |
568 | int srcu_notifier_call_chain(struct srcu_notifier_head *nh, |
569 | unsigned long val, void *v) | |
570 | { | |
571 | return __srcu_notifier_call_chain(nh, val, v, -1, NULL); | |
572 | } | |
eabc0694 AS |
573 | EXPORT_SYMBOL_GPL(srcu_notifier_call_chain); |
574 | ||
575 | /** | |
576 | * srcu_init_notifier_head - Initialize an SRCU notifier head | |
577 | * @nh: Pointer to head of the srcu notifier chain | |
578 | * | |
579 | * Unlike other sorts of notifier heads, SRCU notifier heads require | |
580 | * dynamic initialization. Be sure to call this routine before | |
581 | * calling any of the other SRCU notifier routines for this head. | |
582 | * | |
583 | * If an SRCU notifier head is deallocated, it must first be cleaned | |
584 | * up by calling srcu_cleanup_notifier_head(). Otherwise the head's | |
585 | * per-cpu data (used by the SRCU mechanism) will leak. | |
586 | */ | |
587 | ||
588 | void srcu_init_notifier_head(struct srcu_notifier_head *nh) | |
589 | { | |
590 | mutex_init(&nh->mutex); | |
e6a92013 AS |
591 | if (init_srcu_struct(&nh->srcu) < 0) |
592 | BUG(); | |
eabc0694 AS |
593 | nh->head = NULL; |
594 | } | |
595 | ||
596 | EXPORT_SYMBOL_GPL(srcu_init_notifier_head); | |
597 | ||
1da177e4 LT |
598 | /** |
599 | * register_reboot_notifier - Register function to be called at reboot time | |
600 | * @nb: Info about notifier function to be called | |
601 | * | |
602 | * Registers a function with the list of functions | |
603 | * to be called at reboot time. | |
604 | * | |
72fd4a35 | 605 | * Currently always returns zero, as blocking_notifier_chain_register() |
1da177e4 LT |
606 | * always returns zero. |
607 | */ | |
608 | ||
609 | int register_reboot_notifier(struct notifier_block * nb) | |
610 | { | |
e041c683 | 611 | return blocking_notifier_chain_register(&reboot_notifier_list, nb); |
1da177e4 LT |
612 | } |
613 | ||
614 | EXPORT_SYMBOL(register_reboot_notifier); | |
615 | ||
616 | /** | |
617 | * unregister_reboot_notifier - Unregister previously registered reboot notifier | |
618 | * @nb: Hook to be unregistered | |
619 | * | |
620 | * Unregisters a previously registered reboot | |
621 | * notifier function. | |
622 | * | |
623 | * Returns zero on success, or %-ENOENT on failure. | |
624 | */ | |
625 | ||
626 | int unregister_reboot_notifier(struct notifier_block * nb) | |
627 | { | |
e041c683 | 628 | return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); |
1da177e4 LT |
629 | } |
630 | ||
631 | EXPORT_SYMBOL(unregister_reboot_notifier); | |
632 | ||
633 | static int set_one_prio(struct task_struct *p, int niceval, int error) | |
634 | { | |
635 | int no_nice; | |
636 | ||
637 | if (p->uid != current->euid && | |
638 | p->euid != current->euid && !capable(CAP_SYS_NICE)) { | |
639 | error = -EPERM; | |
640 | goto out; | |
641 | } | |
e43379f1 | 642 | if (niceval < task_nice(p) && !can_nice(p, niceval)) { |
1da177e4 LT |
643 | error = -EACCES; |
644 | goto out; | |
645 | } | |
646 | no_nice = security_task_setnice(p, niceval); | |
647 | if (no_nice) { | |
648 | error = no_nice; | |
649 | goto out; | |
650 | } | |
651 | if (error == -ESRCH) | |
652 | error = 0; | |
653 | set_user_nice(p, niceval); | |
654 | out: | |
655 | return error; | |
656 | } | |
657 | ||
658 | asmlinkage long sys_setpriority(int which, int who, int niceval) | |
659 | { | |
660 | struct task_struct *g, *p; | |
661 | struct user_struct *user; | |
662 | int error = -EINVAL; | |
41487c65 | 663 | struct pid *pgrp; |
1da177e4 | 664 | |
3e88c553 | 665 | if (which > PRIO_USER || which < PRIO_PROCESS) |
1da177e4 LT |
666 | goto out; |
667 | ||
668 | /* normalize: avoid signed division (rounding problems) */ | |
669 | error = -ESRCH; | |
670 | if (niceval < -20) | |
671 | niceval = -20; | |
672 | if (niceval > 19) | |
673 | niceval = 19; | |
674 | ||
675 | read_lock(&tasklist_lock); | |
676 | switch (which) { | |
677 | case PRIO_PROCESS: | |
41487c65 EB |
678 | if (who) |
679 | p = find_task_by_pid(who); | |
680 | else | |
681 | p = current; | |
1da177e4 LT |
682 | if (p) |
683 | error = set_one_prio(p, niceval, error); | |
684 | break; | |
685 | case PRIO_PGRP: | |
41487c65 EB |
686 | if (who) |
687 | pgrp = find_pid(who); | |
688 | else | |
689 | pgrp = task_pgrp(current); | |
690 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { | |
1da177e4 | 691 | error = set_one_prio(p, niceval, error); |
41487c65 | 692 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
693 | break; |
694 | case PRIO_USER: | |
695 | user = current->user; | |
696 | if (!who) | |
697 | who = current->uid; | |
698 | else | |
699 | if ((who != current->uid) && !(user = find_user(who))) | |
700 | goto out_unlock; /* No processes for this user */ | |
701 | ||
702 | do_each_thread(g, p) | |
703 | if (p->uid == who) | |
704 | error = set_one_prio(p, niceval, error); | |
705 | while_each_thread(g, p); | |
706 | if (who != current->uid) | |
707 | free_uid(user); /* For find_user() */ | |
708 | break; | |
709 | } | |
710 | out_unlock: | |
711 | read_unlock(&tasklist_lock); | |
712 | out: | |
713 | return error; | |
714 | } | |
715 | ||
716 | /* | |
717 | * Ugh. To avoid negative return values, "getpriority()" will | |
718 | * not return the normal nice-value, but a negated value that | |
719 | * has been offset by 20 (ie it returns 40..1 instead of -20..19) | |
720 | * to stay compatible. | |
721 | */ | |
722 | asmlinkage long sys_getpriority(int which, int who) | |
723 | { | |
724 | struct task_struct *g, *p; | |
725 | struct user_struct *user; | |
726 | long niceval, retval = -ESRCH; | |
41487c65 | 727 | struct pid *pgrp; |
1da177e4 | 728 | |
3e88c553 | 729 | if (which > PRIO_USER || which < PRIO_PROCESS) |
1da177e4 LT |
730 | return -EINVAL; |
731 | ||
732 | read_lock(&tasklist_lock); | |
733 | switch (which) { | |
734 | case PRIO_PROCESS: | |
41487c65 EB |
735 | if (who) |
736 | p = find_task_by_pid(who); | |
737 | else | |
738 | p = current; | |
1da177e4 LT |
739 | if (p) { |
740 | niceval = 20 - task_nice(p); | |
741 | if (niceval > retval) | |
742 | retval = niceval; | |
743 | } | |
744 | break; | |
745 | case PRIO_PGRP: | |
41487c65 EB |
746 | if (who) |
747 | pgrp = find_pid(who); | |
748 | else | |
749 | pgrp = task_pgrp(current); | |
750 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { | |
1da177e4 LT |
751 | niceval = 20 - task_nice(p); |
752 | if (niceval > retval) | |
753 | retval = niceval; | |
41487c65 | 754 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
755 | break; |
756 | case PRIO_USER: | |
757 | user = current->user; | |
758 | if (!who) | |
759 | who = current->uid; | |
760 | else | |
761 | if ((who != current->uid) && !(user = find_user(who))) | |
762 | goto out_unlock; /* No processes for this user */ | |
763 | ||
764 | do_each_thread(g, p) | |
765 | if (p->uid == who) { | |
766 | niceval = 20 - task_nice(p); | |
767 | if (niceval > retval) | |
768 | retval = niceval; | |
769 | } | |
770 | while_each_thread(g, p); | |
771 | if (who != current->uid) | |
772 | free_uid(user); /* for find_user() */ | |
773 | break; | |
774 | } | |
775 | out_unlock: | |
776 | read_unlock(&tasklist_lock); | |
777 | ||
778 | return retval; | |
779 | } | |
780 | ||
e4c94330 EB |
781 | /** |
782 | * emergency_restart - reboot the system | |
783 | * | |
784 | * Without shutting down any hardware or taking any locks | |
785 | * reboot the system. This is called when we know we are in | |
786 | * trouble so this is our best effort to reboot. This is | |
787 | * safe to call in interrupt context. | |
788 | */ | |
7c903473 EB |
789 | void emergency_restart(void) |
790 | { | |
791 | machine_emergency_restart(); | |
792 | } | |
793 | EXPORT_SYMBOL_GPL(emergency_restart); | |
794 | ||
83cc5ed3 | 795 | static void kernel_restart_prepare(char *cmd) |
4a00ea1e | 796 | { |
e041c683 | 797 | blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); |
4a00ea1e | 798 | system_state = SYSTEM_RESTART; |
4a00ea1e | 799 | device_shutdown(); |
e4c94330 | 800 | } |
1e5d5331 RD |
801 | |
802 | /** | |
803 | * kernel_restart - reboot the system | |
804 | * @cmd: pointer to buffer containing command to execute for restart | |
b8887e6e | 805 | * or %NULL |
1e5d5331 RD |
806 | * |
807 | * Shutdown everything and perform a clean reboot. | |
808 | * This is not safe to call in interrupt context. | |
809 | */ | |
e4c94330 EB |
810 | void kernel_restart(char *cmd) |
811 | { | |
812 | kernel_restart_prepare(cmd); | |
756184b7 | 813 | if (!cmd) |
4a00ea1e | 814 | printk(KERN_EMERG "Restarting system.\n"); |
756184b7 | 815 | else |
4a00ea1e | 816 | printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); |
4a00ea1e EB |
817 | machine_restart(cmd); |
818 | } | |
819 | EXPORT_SYMBOL_GPL(kernel_restart); | |
820 | ||
e4c94330 EB |
821 | /** |
822 | * kernel_kexec - reboot the system | |
823 | * | |
824 | * Move into place and start executing a preloaded standalone | |
825 | * executable. If nothing was preloaded return an error. | |
826 | */ | |
83cc5ed3 | 827 | static void kernel_kexec(void) |
4a00ea1e EB |
828 | { |
829 | #ifdef CONFIG_KEXEC | |
830 | struct kimage *image; | |
4bb8089c | 831 | image = xchg(&kexec_image, NULL); |
756184b7 | 832 | if (!image) |
4a00ea1e | 833 | return; |
e4c94330 | 834 | kernel_restart_prepare(NULL); |
4a00ea1e EB |
835 | printk(KERN_EMERG "Starting new kernel\n"); |
836 | machine_shutdown(); | |
837 | machine_kexec(image); | |
838 | #endif | |
839 | } | |
4a00ea1e | 840 | |
729b4d4c AS |
841 | void kernel_shutdown_prepare(enum system_states state) |
842 | { | |
e041c683 | 843 | blocking_notifier_call_chain(&reboot_notifier_list, |
729b4d4c AS |
844 | (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); |
845 | system_state = state; | |
846 | device_shutdown(); | |
847 | } | |
e4c94330 EB |
848 | /** |
849 | * kernel_halt - halt the system | |
850 | * | |
851 | * Shutdown everything and perform a clean system halt. | |
852 | */ | |
e4c94330 EB |
853 | void kernel_halt(void) |
854 | { | |
729b4d4c | 855 | kernel_shutdown_prepare(SYSTEM_HALT); |
4a00ea1e EB |
856 | printk(KERN_EMERG "System halted.\n"); |
857 | machine_halt(); | |
858 | } | |
729b4d4c | 859 | |
4a00ea1e EB |
860 | EXPORT_SYMBOL_GPL(kernel_halt); |
861 | ||
e4c94330 EB |
862 | /** |
863 | * kernel_power_off - power_off the system | |
864 | * | |
865 | * Shutdown everything and perform a clean system power_off. | |
866 | */ | |
e4c94330 EB |
867 | void kernel_power_off(void) |
868 | { | |
729b4d4c | 869 | kernel_shutdown_prepare(SYSTEM_POWER_OFF); |
4a00ea1e EB |
870 | printk(KERN_EMERG "Power down.\n"); |
871 | machine_power_off(); | |
872 | } | |
873 | EXPORT_SYMBOL_GPL(kernel_power_off); | |
1da177e4 LT |
874 | /* |
875 | * Reboot system call: for obvious reasons only root may call it, | |
876 | * and even root needs to set up some magic numbers in the registers | |
877 | * so that some mistake won't make this reboot the whole machine. | |
878 | * You can also set the meaning of the ctrl-alt-del-key here. | |
879 | * | |
880 | * reboot doesn't sync: do that yourself before calling this. | |
881 | */ | |
882 | asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg) | |
883 | { | |
884 | char buffer[256]; | |
885 | ||
886 | /* We only trust the superuser with rebooting the system. */ | |
887 | if (!capable(CAP_SYS_BOOT)) | |
888 | return -EPERM; | |
889 | ||
890 | /* For safety, we require "magic" arguments. */ | |
891 | if (magic1 != LINUX_REBOOT_MAGIC1 || | |
892 | (magic2 != LINUX_REBOOT_MAGIC2 && | |
893 | magic2 != LINUX_REBOOT_MAGIC2A && | |
894 | magic2 != LINUX_REBOOT_MAGIC2B && | |
895 | magic2 != LINUX_REBOOT_MAGIC2C)) | |
896 | return -EINVAL; | |
897 | ||
5e38291d EB |
898 | /* Instead of trying to make the power_off code look like |
899 | * halt when pm_power_off is not set do it the easy way. | |
900 | */ | |
901 | if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) | |
902 | cmd = LINUX_REBOOT_CMD_HALT; | |
903 | ||
1da177e4 LT |
904 | lock_kernel(); |
905 | switch (cmd) { | |
906 | case LINUX_REBOOT_CMD_RESTART: | |
4a00ea1e | 907 | kernel_restart(NULL); |
1da177e4 LT |
908 | break; |
909 | ||
910 | case LINUX_REBOOT_CMD_CAD_ON: | |
911 | C_A_D = 1; | |
912 | break; | |
913 | ||
914 | case LINUX_REBOOT_CMD_CAD_OFF: | |
915 | C_A_D = 0; | |
916 | break; | |
917 | ||
918 | case LINUX_REBOOT_CMD_HALT: | |
4a00ea1e | 919 | kernel_halt(); |
1da177e4 LT |
920 | unlock_kernel(); |
921 | do_exit(0); | |
922 | break; | |
923 | ||
924 | case LINUX_REBOOT_CMD_POWER_OFF: | |
4a00ea1e | 925 | kernel_power_off(); |
1da177e4 LT |
926 | unlock_kernel(); |
927 | do_exit(0); | |
928 | break; | |
929 | ||
930 | case LINUX_REBOOT_CMD_RESTART2: | |
931 | if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { | |
932 | unlock_kernel(); | |
933 | return -EFAULT; | |
934 | } | |
935 | buffer[sizeof(buffer) - 1] = '\0'; | |
936 | ||
4a00ea1e | 937 | kernel_restart(buffer); |
1da177e4 LT |
938 | break; |
939 | ||
dc009d92 | 940 | case LINUX_REBOOT_CMD_KEXEC: |
4a00ea1e EB |
941 | kernel_kexec(); |
942 | unlock_kernel(); | |
943 | return -EINVAL; | |
944 | ||
1da177e4 LT |
945 | #ifdef CONFIG_SOFTWARE_SUSPEND |
946 | case LINUX_REBOOT_CMD_SW_SUSPEND: | |
947 | { | |
a3d25c27 | 948 | int ret = hibernate(); |
1da177e4 LT |
949 | unlock_kernel(); |
950 | return ret; | |
951 | } | |
952 | #endif | |
953 | ||
954 | default: | |
955 | unlock_kernel(); | |
956 | return -EINVAL; | |
957 | } | |
958 | unlock_kernel(); | |
959 | return 0; | |
960 | } | |
961 | ||
65f27f38 | 962 | static void deferred_cad(struct work_struct *dummy) |
1da177e4 | 963 | { |
abcd9e51 | 964 | kernel_restart(NULL); |
1da177e4 LT |
965 | } |
966 | ||
967 | /* | |
968 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. | |
969 | * As it's called within an interrupt, it may NOT sync: the only choice | |
970 | * is whether to reboot at once, or just ignore the ctrl-alt-del. | |
971 | */ | |
972 | void ctrl_alt_del(void) | |
973 | { | |
65f27f38 | 974 | static DECLARE_WORK(cad_work, deferred_cad); |
1da177e4 LT |
975 | |
976 | if (C_A_D) | |
977 | schedule_work(&cad_work); | |
978 | else | |
9ec52099 | 979 | kill_cad_pid(SIGINT, 1); |
1da177e4 LT |
980 | } |
981 | ||
1da177e4 LT |
982 | /* |
983 | * Unprivileged users may change the real gid to the effective gid | |
984 | * or vice versa. (BSD-style) | |
985 | * | |
986 | * If you set the real gid at all, or set the effective gid to a value not | |
987 | * equal to the real gid, then the saved gid is set to the new effective gid. | |
988 | * | |
989 | * This makes it possible for a setgid program to completely drop its | |
990 | * privileges, which is often a useful assertion to make when you are doing | |
991 | * a security audit over a program. | |
992 | * | |
993 | * The general idea is that a program which uses just setregid() will be | |
994 | * 100% compatible with BSD. A program which uses just setgid() will be | |
995 | * 100% compatible with POSIX with saved IDs. | |
996 | * | |
997 | * SMP: There are not races, the GIDs are checked only by filesystem | |
998 | * operations (as far as semantic preservation is concerned). | |
999 | */ | |
1000 | asmlinkage long sys_setregid(gid_t rgid, gid_t egid) | |
1001 | { | |
1002 | int old_rgid = current->gid; | |
1003 | int old_egid = current->egid; | |
1004 | int new_rgid = old_rgid; | |
1005 | int new_egid = old_egid; | |
1006 | int retval; | |
1007 | ||
1008 | retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE); | |
1009 | if (retval) | |
1010 | return retval; | |
1011 | ||
1012 | if (rgid != (gid_t) -1) { | |
1013 | if ((old_rgid == rgid) || | |
1014 | (current->egid==rgid) || | |
1015 | capable(CAP_SETGID)) | |
1016 | new_rgid = rgid; | |
1017 | else | |
1018 | return -EPERM; | |
1019 | } | |
1020 | if (egid != (gid_t) -1) { | |
1021 | if ((old_rgid == egid) || | |
1022 | (current->egid == egid) || | |
1023 | (current->sgid == egid) || | |
1024 | capable(CAP_SETGID)) | |
1025 | new_egid = egid; | |
756184b7 | 1026 | else |
1da177e4 | 1027 | return -EPERM; |
1da177e4 | 1028 | } |
756184b7 | 1029 | if (new_egid != old_egid) { |
d6e71144 | 1030 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1031 | smp_wmb(); |
1da177e4 LT |
1032 | } |
1033 | if (rgid != (gid_t) -1 || | |
1034 | (egid != (gid_t) -1 && egid != old_rgid)) | |
1035 | current->sgid = new_egid; | |
1036 | current->fsgid = new_egid; | |
1037 | current->egid = new_egid; | |
1038 | current->gid = new_rgid; | |
1039 | key_fsgid_changed(current); | |
9f46080c | 1040 | proc_id_connector(current, PROC_EVENT_GID); |
1da177e4 LT |
1041 | return 0; |
1042 | } | |
1043 | ||
1044 | /* | |
1045 | * setgid() is implemented like SysV w/ SAVED_IDS | |
1046 | * | |
1047 | * SMP: Same implicit races as above. | |
1048 | */ | |
1049 | asmlinkage long sys_setgid(gid_t gid) | |
1050 | { | |
1051 | int old_egid = current->egid; | |
1052 | int retval; | |
1053 | ||
1054 | retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID); | |
1055 | if (retval) | |
1056 | return retval; | |
1057 | ||
756184b7 CP |
1058 | if (capable(CAP_SETGID)) { |
1059 | if (old_egid != gid) { | |
d6e71144 | 1060 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1061 | smp_wmb(); |
1da177e4 LT |
1062 | } |
1063 | current->gid = current->egid = current->sgid = current->fsgid = gid; | |
756184b7 CP |
1064 | } else if ((gid == current->gid) || (gid == current->sgid)) { |
1065 | if (old_egid != gid) { | |
d6e71144 | 1066 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1067 | smp_wmb(); |
1da177e4 LT |
1068 | } |
1069 | current->egid = current->fsgid = gid; | |
1070 | } | |
1071 | else | |
1072 | return -EPERM; | |
1073 | ||
1074 | key_fsgid_changed(current); | |
9f46080c | 1075 | proc_id_connector(current, PROC_EVENT_GID); |
1da177e4 LT |
1076 | return 0; |
1077 | } | |
1078 | ||
1079 | static int set_user(uid_t new_ruid, int dumpclear) | |
1080 | { | |
1081 | struct user_struct *new_user; | |
1082 | ||
acce292c | 1083 | new_user = alloc_uid(current->nsproxy->user_ns, new_ruid); |
1da177e4 LT |
1084 | if (!new_user) |
1085 | return -EAGAIN; | |
1086 | ||
1087 | if (atomic_read(&new_user->processes) >= | |
1088 | current->signal->rlim[RLIMIT_NPROC].rlim_cur && | |
acce292c | 1089 | new_user != current->nsproxy->user_ns->root_user) { |
1da177e4 LT |
1090 | free_uid(new_user); |
1091 | return -EAGAIN; | |
1092 | } | |
1093 | ||
1094 | switch_uid(new_user); | |
1095 | ||
756184b7 | 1096 | if (dumpclear) { |
d6e71144 | 1097 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1098 | smp_wmb(); |
1da177e4 LT |
1099 | } |
1100 | current->uid = new_ruid; | |
1101 | return 0; | |
1102 | } | |
1103 | ||
1104 | /* | |
1105 | * Unprivileged users may change the real uid to the effective uid | |
1106 | * or vice versa. (BSD-style) | |
1107 | * | |
1108 | * If you set the real uid at all, or set the effective uid to a value not | |
1109 | * equal to the real uid, then the saved uid is set to the new effective uid. | |
1110 | * | |
1111 | * This makes it possible for a setuid program to completely drop its | |
1112 | * privileges, which is often a useful assertion to make when you are doing | |
1113 | * a security audit over a program. | |
1114 | * | |
1115 | * The general idea is that a program which uses just setreuid() will be | |
1116 | * 100% compatible with BSD. A program which uses just setuid() will be | |
1117 | * 100% compatible with POSIX with saved IDs. | |
1118 | */ | |
1119 | asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) | |
1120 | { | |
1121 | int old_ruid, old_euid, old_suid, new_ruid, new_euid; | |
1122 | int retval; | |
1123 | ||
1124 | retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE); | |
1125 | if (retval) | |
1126 | return retval; | |
1127 | ||
1128 | new_ruid = old_ruid = current->uid; | |
1129 | new_euid = old_euid = current->euid; | |
1130 | old_suid = current->suid; | |
1131 | ||
1132 | if (ruid != (uid_t) -1) { | |
1133 | new_ruid = ruid; | |
1134 | if ((old_ruid != ruid) && | |
1135 | (current->euid != ruid) && | |
1136 | !capable(CAP_SETUID)) | |
1137 | return -EPERM; | |
1138 | } | |
1139 | ||
1140 | if (euid != (uid_t) -1) { | |
1141 | new_euid = euid; | |
1142 | if ((old_ruid != euid) && | |
1143 | (current->euid != euid) && | |
1144 | (current->suid != euid) && | |
1145 | !capable(CAP_SETUID)) | |
1146 | return -EPERM; | |
1147 | } | |
1148 | ||
1149 | if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0) | |
1150 | return -EAGAIN; | |
1151 | ||
756184b7 | 1152 | if (new_euid != old_euid) { |
d6e71144 | 1153 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1154 | smp_wmb(); |
1da177e4 LT |
1155 | } |
1156 | current->fsuid = current->euid = new_euid; | |
1157 | if (ruid != (uid_t) -1 || | |
1158 | (euid != (uid_t) -1 && euid != old_ruid)) | |
1159 | current->suid = current->euid; | |
1160 | current->fsuid = current->euid; | |
1161 | ||
1162 | key_fsuid_changed(current); | |
9f46080c | 1163 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1164 | |
1165 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE); | |
1166 | } | |
1167 | ||
1168 | ||
1169 | ||
1170 | /* | |
1171 | * setuid() is implemented like SysV with SAVED_IDS | |
1172 | * | |
1173 | * Note that SAVED_ID's is deficient in that a setuid root program | |
1174 | * like sendmail, for example, cannot set its uid to be a normal | |
1175 | * user and then switch back, because if you're root, setuid() sets | |
1176 | * the saved uid too. If you don't like this, blame the bright people | |
1177 | * in the POSIX committee and/or USG. Note that the BSD-style setreuid() | |
1178 | * will allow a root program to temporarily drop privileges and be able to | |
1179 | * regain them by swapping the real and effective uid. | |
1180 | */ | |
1181 | asmlinkage long sys_setuid(uid_t uid) | |
1182 | { | |
1183 | int old_euid = current->euid; | |
a09c17a6 | 1184 | int old_ruid, old_suid, new_suid; |
1da177e4 LT |
1185 | int retval; |
1186 | ||
1187 | retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID); | |
1188 | if (retval) | |
1189 | return retval; | |
1190 | ||
a09c17a6 | 1191 | old_ruid = current->uid; |
1da177e4 LT |
1192 | old_suid = current->suid; |
1193 | new_suid = old_suid; | |
1194 | ||
1195 | if (capable(CAP_SETUID)) { | |
1196 | if (uid != old_ruid && set_user(uid, old_euid != uid) < 0) | |
1197 | return -EAGAIN; | |
1198 | new_suid = uid; | |
1199 | } else if ((uid != current->uid) && (uid != new_suid)) | |
1200 | return -EPERM; | |
1201 | ||
756184b7 | 1202 | if (old_euid != uid) { |
d6e71144 | 1203 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1204 | smp_wmb(); |
1da177e4 LT |
1205 | } |
1206 | current->fsuid = current->euid = uid; | |
1207 | current->suid = new_suid; | |
1208 | ||
1209 | key_fsuid_changed(current); | |
9f46080c | 1210 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1211 | |
1212 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID); | |
1213 | } | |
1214 | ||
1215 | ||
1216 | /* | |
1217 | * This function implements a generic ability to update ruid, euid, | |
1218 | * and suid. This allows you to implement the 4.4 compatible seteuid(). | |
1219 | */ | |
1220 | asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) | |
1221 | { | |
1222 | int old_ruid = current->uid; | |
1223 | int old_euid = current->euid; | |
1224 | int old_suid = current->suid; | |
1225 | int retval; | |
1226 | ||
1227 | retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES); | |
1228 | if (retval) | |
1229 | return retval; | |
1230 | ||
1231 | if (!capable(CAP_SETUID)) { | |
1232 | if ((ruid != (uid_t) -1) && (ruid != current->uid) && | |
1233 | (ruid != current->euid) && (ruid != current->suid)) | |
1234 | return -EPERM; | |
1235 | if ((euid != (uid_t) -1) && (euid != current->uid) && | |
1236 | (euid != current->euid) && (euid != current->suid)) | |
1237 | return -EPERM; | |
1238 | if ((suid != (uid_t) -1) && (suid != current->uid) && | |
1239 | (suid != current->euid) && (suid != current->suid)) | |
1240 | return -EPERM; | |
1241 | } | |
1242 | if (ruid != (uid_t) -1) { | |
1243 | if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0) | |
1244 | return -EAGAIN; | |
1245 | } | |
1246 | if (euid != (uid_t) -1) { | |
756184b7 | 1247 | if (euid != current->euid) { |
d6e71144 | 1248 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1249 | smp_wmb(); |
1da177e4 LT |
1250 | } |
1251 | current->euid = euid; | |
1252 | } | |
1253 | current->fsuid = current->euid; | |
1254 | if (suid != (uid_t) -1) | |
1255 | current->suid = suid; | |
1256 | ||
1257 | key_fsuid_changed(current); | |
9f46080c | 1258 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1259 | |
1260 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES); | |
1261 | } | |
1262 | ||
1263 | asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid) | |
1264 | { | |
1265 | int retval; | |
1266 | ||
1267 | if (!(retval = put_user(current->uid, ruid)) && | |
1268 | !(retval = put_user(current->euid, euid))) | |
1269 | retval = put_user(current->suid, suid); | |
1270 | ||
1271 | return retval; | |
1272 | } | |
1273 | ||
1274 | /* | |
1275 | * Same as above, but for rgid, egid, sgid. | |
1276 | */ | |
1277 | asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) | |
1278 | { | |
1279 | int retval; | |
1280 | ||
1281 | retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES); | |
1282 | if (retval) | |
1283 | return retval; | |
1284 | ||
1285 | if (!capable(CAP_SETGID)) { | |
1286 | if ((rgid != (gid_t) -1) && (rgid != current->gid) && | |
1287 | (rgid != current->egid) && (rgid != current->sgid)) | |
1288 | return -EPERM; | |
1289 | if ((egid != (gid_t) -1) && (egid != current->gid) && | |
1290 | (egid != current->egid) && (egid != current->sgid)) | |
1291 | return -EPERM; | |
1292 | if ((sgid != (gid_t) -1) && (sgid != current->gid) && | |
1293 | (sgid != current->egid) && (sgid != current->sgid)) | |
1294 | return -EPERM; | |
1295 | } | |
1296 | if (egid != (gid_t) -1) { | |
756184b7 | 1297 | if (egid != current->egid) { |
d6e71144 | 1298 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1299 | smp_wmb(); |
1da177e4 LT |
1300 | } |
1301 | current->egid = egid; | |
1302 | } | |
1303 | current->fsgid = current->egid; | |
1304 | if (rgid != (gid_t) -1) | |
1305 | current->gid = rgid; | |
1306 | if (sgid != (gid_t) -1) | |
1307 | current->sgid = sgid; | |
1308 | ||
1309 | key_fsgid_changed(current); | |
9f46080c | 1310 | proc_id_connector(current, PROC_EVENT_GID); |
1da177e4 LT |
1311 | return 0; |
1312 | } | |
1313 | ||
1314 | asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid) | |
1315 | { | |
1316 | int retval; | |
1317 | ||
1318 | if (!(retval = put_user(current->gid, rgid)) && | |
1319 | !(retval = put_user(current->egid, egid))) | |
1320 | retval = put_user(current->sgid, sgid); | |
1321 | ||
1322 | return retval; | |
1323 | } | |
1324 | ||
1325 | ||
1326 | /* | |
1327 | * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This | |
1328 | * is used for "access()" and for the NFS daemon (letting nfsd stay at | |
1329 | * whatever uid it wants to). It normally shadows "euid", except when | |
1330 | * explicitly set by setfsuid() or for access.. | |
1331 | */ | |
1332 | asmlinkage long sys_setfsuid(uid_t uid) | |
1333 | { | |
1334 | int old_fsuid; | |
1335 | ||
1336 | old_fsuid = current->fsuid; | |
1337 | if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS)) | |
1338 | return old_fsuid; | |
1339 | ||
1340 | if (uid == current->uid || uid == current->euid || | |
1341 | uid == current->suid || uid == current->fsuid || | |
756184b7 CP |
1342 | capable(CAP_SETUID)) { |
1343 | if (uid != old_fsuid) { | |
d6e71144 | 1344 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1345 | smp_wmb(); |
1da177e4 LT |
1346 | } |
1347 | current->fsuid = uid; | |
1348 | } | |
1349 | ||
1350 | key_fsuid_changed(current); | |
9f46080c | 1351 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1352 | |
1353 | security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); | |
1354 | ||
1355 | return old_fsuid; | |
1356 | } | |
1357 | ||
1358 | /* | |
f42df9e6 | 1359 | * Samma på svenska.. |
1da177e4 LT |
1360 | */ |
1361 | asmlinkage long sys_setfsgid(gid_t gid) | |
1362 | { | |
1363 | int old_fsgid; | |
1364 | ||
1365 | old_fsgid = current->fsgid; | |
1366 | if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS)) | |
1367 | return old_fsgid; | |
1368 | ||
1369 | if (gid == current->gid || gid == current->egid || | |
1370 | gid == current->sgid || gid == current->fsgid || | |
756184b7 CP |
1371 | capable(CAP_SETGID)) { |
1372 | if (gid != old_fsgid) { | |
d6e71144 | 1373 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1374 | smp_wmb(); |
1da177e4 LT |
1375 | } |
1376 | current->fsgid = gid; | |
1377 | key_fsgid_changed(current); | |
9f46080c | 1378 | proc_id_connector(current, PROC_EVENT_GID); |
1da177e4 LT |
1379 | } |
1380 | return old_fsgid; | |
1381 | } | |
1382 | ||
1383 | asmlinkage long sys_times(struct tms __user * tbuf) | |
1384 | { | |
1385 | /* | |
1386 | * In the SMP world we might just be unlucky and have one of | |
1387 | * the times increment as we use it. Since the value is an | |
1388 | * atomically safe type this is just fine. Conceptually its | |
1389 | * as if the syscall took an instant longer to occur. | |
1390 | */ | |
1391 | if (tbuf) { | |
1392 | struct tms tmp; | |
35f5cad8 ON |
1393 | struct task_struct *tsk = current; |
1394 | struct task_struct *t; | |
1da177e4 LT |
1395 | cputime_t utime, stime, cutime, cstime; |
1396 | ||
7d7185c8 | 1397 | spin_lock_irq(&tsk->sighand->siglock); |
35f5cad8 ON |
1398 | utime = tsk->signal->utime; |
1399 | stime = tsk->signal->stime; | |
1400 | t = tsk; | |
1401 | do { | |
1402 | utime = cputime_add(utime, t->utime); | |
1403 | stime = cputime_add(stime, t->stime); | |
1404 | t = next_thread(t); | |
1405 | } while (t != tsk); | |
1406 | ||
35f5cad8 ON |
1407 | cutime = tsk->signal->cutime; |
1408 | cstime = tsk->signal->cstime; | |
1409 | spin_unlock_irq(&tsk->sighand->siglock); | |
1da177e4 LT |
1410 | |
1411 | tmp.tms_utime = cputime_to_clock_t(utime); | |
1412 | tmp.tms_stime = cputime_to_clock_t(stime); | |
1413 | tmp.tms_cutime = cputime_to_clock_t(cutime); | |
1414 | tmp.tms_cstime = cputime_to_clock_t(cstime); | |
1415 | if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) | |
1416 | return -EFAULT; | |
1417 | } | |
1418 | return (long) jiffies_64_to_clock_t(get_jiffies_64()); | |
1419 | } | |
1420 | ||
1421 | /* | |
1422 | * This needs some heavy checking ... | |
1423 | * I just haven't the stomach for it. I also don't fully | |
1424 | * understand sessions/pgrp etc. Let somebody who does explain it. | |
1425 | * | |
1426 | * OK, I think I have the protection semantics right.... this is really | |
1427 | * only important on a multi-user system anyway, to make sure one user | |
1428 | * can't send a signal to a process owned by another. -TYT, 12/12/91 | |
1429 | * | |
1430 | * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. | |
1431 | * LBT 04.03.94 | |
1432 | */ | |
1433 | ||
1434 | asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) | |
1435 | { | |
1436 | struct task_struct *p; | |
ee0acf90 | 1437 | struct task_struct *group_leader = current->group_leader; |
1da177e4 LT |
1438 | int err = -EINVAL; |
1439 | ||
1440 | if (!pid) | |
ee0acf90 | 1441 | pid = group_leader->pid; |
1da177e4 LT |
1442 | if (!pgid) |
1443 | pgid = pid; | |
1444 | if (pgid < 0) | |
1445 | return -EINVAL; | |
1446 | ||
1447 | /* From this point forward we keep holding onto the tasklist lock | |
1448 | * so that our parent does not change from under us. -DaveM | |
1449 | */ | |
1450 | write_lock_irq(&tasklist_lock); | |
1451 | ||
1452 | err = -ESRCH; | |
1453 | p = find_task_by_pid(pid); | |
1454 | if (!p) | |
1455 | goto out; | |
1456 | ||
1457 | err = -EINVAL; | |
1458 | if (!thread_group_leader(p)) | |
1459 | goto out; | |
1460 | ||
f7dd795e | 1461 | if (p->real_parent == group_leader) { |
1da177e4 | 1462 | err = -EPERM; |
41487c65 | 1463 | if (task_session(p) != task_session(group_leader)) |
1da177e4 LT |
1464 | goto out; |
1465 | err = -EACCES; | |
1466 | if (p->did_exec) | |
1467 | goto out; | |
1468 | } else { | |
1469 | err = -ESRCH; | |
ee0acf90 | 1470 | if (p != group_leader) |
1da177e4 LT |
1471 | goto out; |
1472 | } | |
1473 | ||
1474 | err = -EPERM; | |
1475 | if (p->signal->leader) | |
1476 | goto out; | |
1477 | ||
1478 | if (pgid != pid) { | |
f020bc46 ON |
1479 | struct task_struct *g = |
1480 | find_task_by_pid_type(PIDTYPE_PGID, pgid); | |
1da177e4 | 1481 | |
41487c65 | 1482 | if (!g || task_session(g) != task_session(group_leader)) |
f020bc46 | 1483 | goto out; |
1da177e4 LT |
1484 | } |
1485 | ||
1da177e4 LT |
1486 | err = security_task_setpgid(p, pgid); |
1487 | if (err) | |
1488 | goto out; | |
1489 | ||
1490 | if (process_group(p) != pgid) { | |
1491 | detach_pid(p, PIDTYPE_PGID); | |
1492 | p->signal->pgrp = pgid; | |
e713d0da | 1493 | attach_pid(p, PIDTYPE_PGID, find_pid(pgid)); |
1da177e4 LT |
1494 | } |
1495 | ||
1496 | err = 0; | |
1497 | out: | |
1498 | /* All paths lead to here, thus we are safe. -DaveM */ | |
1499 | write_unlock_irq(&tasklist_lock); | |
1500 | return err; | |
1501 | } | |
1502 | ||
1503 | asmlinkage long sys_getpgid(pid_t pid) | |
1504 | { | |
756184b7 | 1505 | if (!pid) |
1da177e4 | 1506 | return process_group(current); |
756184b7 | 1507 | else { |
1da177e4 LT |
1508 | int retval; |
1509 | struct task_struct *p; | |
1510 | ||
1511 | read_lock(&tasklist_lock); | |
1512 | p = find_task_by_pid(pid); | |
1513 | ||
1514 | retval = -ESRCH; | |
1515 | if (p) { | |
1516 | retval = security_task_getpgid(p); | |
1517 | if (!retval) | |
1518 | retval = process_group(p); | |
1519 | } | |
1520 | read_unlock(&tasklist_lock); | |
1521 | return retval; | |
1522 | } | |
1523 | } | |
1524 | ||
1525 | #ifdef __ARCH_WANT_SYS_GETPGRP | |
1526 | ||
1527 | asmlinkage long sys_getpgrp(void) | |
1528 | { | |
1529 | /* SMP - assuming writes are word atomic this is fine */ | |
1530 | return process_group(current); | |
1531 | } | |
1532 | ||
1533 | #endif | |
1534 | ||
1535 | asmlinkage long sys_getsid(pid_t pid) | |
1536 | { | |
756184b7 | 1537 | if (!pid) |
937949d9 | 1538 | return process_session(current); |
756184b7 | 1539 | else { |
1da177e4 LT |
1540 | int retval; |
1541 | struct task_struct *p; | |
1542 | ||
1543 | read_lock(&tasklist_lock); | |
1544 | p = find_task_by_pid(pid); | |
1545 | ||
1546 | retval = -ESRCH; | |
756184b7 | 1547 | if (p) { |
1da177e4 LT |
1548 | retval = security_task_getsid(p); |
1549 | if (!retval) | |
937949d9 | 1550 | retval = process_session(p); |
1da177e4 LT |
1551 | } |
1552 | read_unlock(&tasklist_lock); | |
1553 | return retval; | |
1554 | } | |
1555 | } | |
1556 | ||
1557 | asmlinkage long sys_setsid(void) | |
1558 | { | |
e19f247a | 1559 | struct task_struct *group_leader = current->group_leader; |
390e2ff0 | 1560 | pid_t session; |
1da177e4 LT |
1561 | int err = -EPERM; |
1562 | ||
1da177e4 LT |
1563 | write_lock_irq(&tasklist_lock); |
1564 | ||
390e2ff0 EB |
1565 | /* Fail if I am already a session leader */ |
1566 | if (group_leader->signal->leader) | |
1567 | goto out; | |
1568 | ||
1569 | session = group_leader->pid; | |
1570 | /* Fail if a process group id already exists that equals the | |
1571 | * proposed session id. | |
1572 | * | |
1573 | * Don't check if session id == 1 because kernel threads use this | |
1574 | * session id and so the check will always fail and make it so | |
1575 | * init cannot successfully call setsid. | |
1576 | */ | |
1577 | if (session > 1 && find_task_by_pid_type(PIDTYPE_PGID, session)) | |
1da177e4 LT |
1578 | goto out; |
1579 | ||
e19f247a | 1580 | group_leader->signal->leader = 1; |
390e2ff0 | 1581 | __set_special_pids(session, session); |
24ec839c PZ |
1582 | |
1583 | spin_lock(&group_leader->sighand->siglock); | |
e19f247a | 1584 | group_leader->signal->tty = NULL; |
24ec839c PZ |
1585 | spin_unlock(&group_leader->sighand->siglock); |
1586 | ||
e19f247a | 1587 | err = process_group(group_leader); |
1da177e4 LT |
1588 | out: |
1589 | write_unlock_irq(&tasklist_lock); | |
1da177e4 LT |
1590 | return err; |
1591 | } | |
1592 | ||
1593 | /* | |
1594 | * Supplementary group IDs | |
1595 | */ | |
1596 | ||
1597 | /* init to 2 - one for init_task, one to ensure it is never freed */ | |
1598 | struct group_info init_groups = { .usage = ATOMIC_INIT(2) }; | |
1599 | ||
1600 | struct group_info *groups_alloc(int gidsetsize) | |
1601 | { | |
1602 | struct group_info *group_info; | |
1603 | int nblocks; | |
1604 | int i; | |
1605 | ||
1606 | nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK; | |
1607 | /* Make sure we always allocate at least one indirect block pointer */ | |
1608 | nblocks = nblocks ? : 1; | |
1609 | group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER); | |
1610 | if (!group_info) | |
1611 | return NULL; | |
1612 | group_info->ngroups = gidsetsize; | |
1613 | group_info->nblocks = nblocks; | |
1614 | atomic_set(&group_info->usage, 1); | |
1615 | ||
756184b7 | 1616 | if (gidsetsize <= NGROUPS_SMALL) |
1da177e4 | 1617 | group_info->blocks[0] = group_info->small_block; |
756184b7 | 1618 | else { |
1da177e4 LT |
1619 | for (i = 0; i < nblocks; i++) { |
1620 | gid_t *b; | |
1621 | b = (void *)__get_free_page(GFP_USER); | |
1622 | if (!b) | |
1623 | goto out_undo_partial_alloc; | |
1624 | group_info->blocks[i] = b; | |
1625 | } | |
1626 | } | |
1627 | return group_info; | |
1628 | ||
1629 | out_undo_partial_alloc: | |
1630 | while (--i >= 0) { | |
1631 | free_page((unsigned long)group_info->blocks[i]); | |
1632 | } | |
1633 | kfree(group_info); | |
1634 | return NULL; | |
1635 | } | |
1636 | ||
1637 | EXPORT_SYMBOL(groups_alloc); | |
1638 | ||
1639 | void groups_free(struct group_info *group_info) | |
1640 | { | |
1641 | if (group_info->blocks[0] != group_info->small_block) { | |
1642 | int i; | |
1643 | for (i = 0; i < group_info->nblocks; i++) | |
1644 | free_page((unsigned long)group_info->blocks[i]); | |
1645 | } | |
1646 | kfree(group_info); | |
1647 | } | |
1648 | ||
1649 | EXPORT_SYMBOL(groups_free); | |
1650 | ||
1651 | /* export the group_info to a user-space array */ | |
1652 | static int groups_to_user(gid_t __user *grouplist, | |
1653 | struct group_info *group_info) | |
1654 | { | |
1655 | int i; | |
1656 | int count = group_info->ngroups; | |
1657 | ||
1658 | for (i = 0; i < group_info->nblocks; i++) { | |
1659 | int cp_count = min(NGROUPS_PER_BLOCK, count); | |
1660 | int off = i * NGROUPS_PER_BLOCK; | |
1661 | int len = cp_count * sizeof(*grouplist); | |
1662 | ||
1663 | if (copy_to_user(grouplist+off, group_info->blocks[i], len)) | |
1664 | return -EFAULT; | |
1665 | ||
1666 | count -= cp_count; | |
1667 | } | |
1668 | return 0; | |
1669 | } | |
1670 | ||
1671 | /* fill a group_info from a user-space array - it must be allocated already */ | |
1672 | static int groups_from_user(struct group_info *group_info, | |
1673 | gid_t __user *grouplist) | |
756184b7 | 1674 | { |
1da177e4 LT |
1675 | int i; |
1676 | int count = group_info->ngroups; | |
1677 | ||
1678 | for (i = 0; i < group_info->nblocks; i++) { | |
1679 | int cp_count = min(NGROUPS_PER_BLOCK, count); | |
1680 | int off = i * NGROUPS_PER_BLOCK; | |
1681 | int len = cp_count * sizeof(*grouplist); | |
1682 | ||
1683 | if (copy_from_user(group_info->blocks[i], grouplist+off, len)) | |
1684 | return -EFAULT; | |
1685 | ||
1686 | count -= cp_count; | |
1687 | } | |
1688 | return 0; | |
1689 | } | |
1690 | ||
ebe8b541 | 1691 | /* a simple Shell sort */ |
1da177e4 LT |
1692 | static void groups_sort(struct group_info *group_info) |
1693 | { | |
1694 | int base, max, stride; | |
1695 | int gidsetsize = group_info->ngroups; | |
1696 | ||
1697 | for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1) | |
1698 | ; /* nothing */ | |
1699 | stride /= 3; | |
1700 | ||
1701 | while (stride) { | |
1702 | max = gidsetsize - stride; | |
1703 | for (base = 0; base < max; base++) { | |
1704 | int left = base; | |
1705 | int right = left + stride; | |
1706 | gid_t tmp = GROUP_AT(group_info, right); | |
1707 | ||
1708 | while (left >= 0 && GROUP_AT(group_info, left) > tmp) { | |
1709 | GROUP_AT(group_info, right) = | |
1710 | GROUP_AT(group_info, left); | |
1711 | right = left; | |
1712 | left -= stride; | |
1713 | } | |
1714 | GROUP_AT(group_info, right) = tmp; | |
1715 | } | |
1716 | stride /= 3; | |
1717 | } | |
1718 | } | |
1719 | ||
1720 | /* a simple bsearch */ | |
3e30148c | 1721 | int groups_search(struct group_info *group_info, gid_t grp) |
1da177e4 | 1722 | { |
d74beb9f | 1723 | unsigned int left, right; |
1da177e4 LT |
1724 | |
1725 | if (!group_info) | |
1726 | return 0; | |
1727 | ||
1728 | left = 0; | |
1729 | right = group_info->ngroups; | |
1730 | while (left < right) { | |
d74beb9f | 1731 | unsigned int mid = (left+right)/2; |
1da177e4 LT |
1732 | int cmp = grp - GROUP_AT(group_info, mid); |
1733 | if (cmp > 0) | |
1734 | left = mid + 1; | |
1735 | else if (cmp < 0) | |
1736 | right = mid; | |
1737 | else | |
1738 | return 1; | |
1739 | } | |
1740 | return 0; | |
1741 | } | |
1742 | ||
1743 | /* validate and set current->group_info */ | |
1744 | int set_current_groups(struct group_info *group_info) | |
1745 | { | |
1746 | int retval; | |
1747 | struct group_info *old_info; | |
1748 | ||
1749 | retval = security_task_setgroups(group_info); | |
1750 | if (retval) | |
1751 | return retval; | |
1752 | ||
1753 | groups_sort(group_info); | |
1754 | get_group_info(group_info); | |
1755 | ||
1756 | task_lock(current); | |
1757 | old_info = current->group_info; | |
1758 | current->group_info = group_info; | |
1759 | task_unlock(current); | |
1760 | ||
1761 | put_group_info(old_info); | |
1762 | ||
1763 | return 0; | |
1764 | } | |
1765 | ||
1766 | EXPORT_SYMBOL(set_current_groups); | |
1767 | ||
1768 | asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist) | |
1769 | { | |
1770 | int i = 0; | |
1771 | ||
1772 | /* | |
1773 | * SMP: Nobody else can change our grouplist. Thus we are | |
1774 | * safe. | |
1775 | */ | |
1776 | ||
1777 | if (gidsetsize < 0) | |
1778 | return -EINVAL; | |
1779 | ||
1780 | /* no need to grab task_lock here; it cannot change */ | |
1da177e4 LT |
1781 | i = current->group_info->ngroups; |
1782 | if (gidsetsize) { | |
1783 | if (i > gidsetsize) { | |
1784 | i = -EINVAL; | |
1785 | goto out; | |
1786 | } | |
1787 | if (groups_to_user(grouplist, current->group_info)) { | |
1788 | i = -EFAULT; | |
1789 | goto out; | |
1790 | } | |
1791 | } | |
1792 | out: | |
1da177e4 LT |
1793 | return i; |
1794 | } | |
1795 | ||
1796 | /* | |
1797 | * SMP: Our groups are copy-on-write. We can set them safely | |
1798 | * without another task interfering. | |
1799 | */ | |
1800 | ||
1801 | asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist) | |
1802 | { | |
1803 | struct group_info *group_info; | |
1804 | int retval; | |
1805 | ||
1806 | if (!capable(CAP_SETGID)) | |
1807 | return -EPERM; | |
1808 | if ((unsigned)gidsetsize > NGROUPS_MAX) | |
1809 | return -EINVAL; | |
1810 | ||
1811 | group_info = groups_alloc(gidsetsize); | |
1812 | if (!group_info) | |
1813 | return -ENOMEM; | |
1814 | retval = groups_from_user(group_info, grouplist); | |
1815 | if (retval) { | |
1816 | put_group_info(group_info); | |
1817 | return retval; | |
1818 | } | |
1819 | ||
1820 | retval = set_current_groups(group_info); | |
1821 | put_group_info(group_info); | |
1822 | ||
1823 | return retval; | |
1824 | } | |
1825 | ||
1826 | /* | |
1827 | * Check whether we're fsgid/egid or in the supplemental group.. | |
1828 | */ | |
1829 | int in_group_p(gid_t grp) | |
1830 | { | |
1831 | int retval = 1; | |
756184b7 | 1832 | if (grp != current->fsgid) |
1da177e4 | 1833 | retval = groups_search(current->group_info, grp); |
1da177e4 LT |
1834 | return retval; |
1835 | } | |
1836 | ||
1837 | EXPORT_SYMBOL(in_group_p); | |
1838 | ||
1839 | int in_egroup_p(gid_t grp) | |
1840 | { | |
1841 | int retval = 1; | |
756184b7 | 1842 | if (grp != current->egid) |
1da177e4 | 1843 | retval = groups_search(current->group_info, grp); |
1da177e4 LT |
1844 | return retval; |
1845 | } | |
1846 | ||
1847 | EXPORT_SYMBOL(in_egroup_p); | |
1848 | ||
1849 | DECLARE_RWSEM(uts_sem); | |
1850 | ||
393b0725 DM |
1851 | EXPORT_SYMBOL(uts_sem); |
1852 | ||
1da177e4 LT |
1853 | asmlinkage long sys_newuname(struct new_utsname __user * name) |
1854 | { | |
1855 | int errno = 0; | |
1856 | ||
1857 | down_read(&uts_sem); | |
e9ff3990 | 1858 | if (copy_to_user(name, utsname(), sizeof *name)) |
1da177e4 LT |
1859 | errno = -EFAULT; |
1860 | up_read(&uts_sem); | |
1861 | return errno; | |
1862 | } | |
1863 | ||
1864 | asmlinkage long sys_sethostname(char __user *name, int len) | |
1865 | { | |
1866 | int errno; | |
1867 | char tmp[__NEW_UTS_LEN]; | |
1868 | ||
1869 | if (!capable(CAP_SYS_ADMIN)) | |
1870 | return -EPERM; | |
1871 | if (len < 0 || len > __NEW_UTS_LEN) | |
1872 | return -EINVAL; | |
1873 | down_write(&uts_sem); | |
1874 | errno = -EFAULT; | |
1875 | if (!copy_from_user(tmp, name, len)) { | |
e9ff3990 SH |
1876 | memcpy(utsname()->nodename, tmp, len); |
1877 | utsname()->nodename[len] = 0; | |
1da177e4 LT |
1878 | errno = 0; |
1879 | } | |
1880 | up_write(&uts_sem); | |
1881 | return errno; | |
1882 | } | |
1883 | ||
1884 | #ifdef __ARCH_WANT_SYS_GETHOSTNAME | |
1885 | ||
1886 | asmlinkage long sys_gethostname(char __user *name, int len) | |
1887 | { | |
1888 | int i, errno; | |
1889 | ||
1890 | if (len < 0) | |
1891 | return -EINVAL; | |
1892 | down_read(&uts_sem); | |
e9ff3990 | 1893 | i = 1 + strlen(utsname()->nodename); |
1da177e4 LT |
1894 | if (i > len) |
1895 | i = len; | |
1896 | errno = 0; | |
e9ff3990 | 1897 | if (copy_to_user(name, utsname()->nodename, i)) |
1da177e4 LT |
1898 | errno = -EFAULT; |
1899 | up_read(&uts_sem); | |
1900 | return errno; | |
1901 | } | |
1902 | ||
1903 | #endif | |
1904 | ||
1905 | /* | |
1906 | * Only setdomainname; getdomainname can be implemented by calling | |
1907 | * uname() | |
1908 | */ | |
1909 | asmlinkage long sys_setdomainname(char __user *name, int len) | |
1910 | { | |
1911 | int errno; | |
1912 | char tmp[__NEW_UTS_LEN]; | |
1913 | ||
1914 | if (!capable(CAP_SYS_ADMIN)) | |
1915 | return -EPERM; | |
1916 | if (len < 0 || len > __NEW_UTS_LEN) | |
1917 | return -EINVAL; | |
1918 | ||
1919 | down_write(&uts_sem); | |
1920 | errno = -EFAULT; | |
1921 | if (!copy_from_user(tmp, name, len)) { | |
e9ff3990 SH |
1922 | memcpy(utsname()->domainname, tmp, len); |
1923 | utsname()->domainname[len] = 0; | |
1da177e4 LT |
1924 | errno = 0; |
1925 | } | |
1926 | up_write(&uts_sem); | |
1927 | return errno; | |
1928 | } | |
1929 | ||
1930 | asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim) | |
1931 | { | |
1932 | if (resource >= RLIM_NLIMITS) | |
1933 | return -EINVAL; | |
1934 | else { | |
1935 | struct rlimit value; | |
1936 | task_lock(current->group_leader); | |
1937 | value = current->signal->rlim[resource]; | |
1938 | task_unlock(current->group_leader); | |
1939 | return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; | |
1940 | } | |
1941 | } | |
1942 | ||
1943 | #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT | |
1944 | ||
1945 | /* | |
1946 | * Back compatibility for getrlimit. Needed for some apps. | |
1947 | */ | |
1948 | ||
1949 | asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim) | |
1950 | { | |
1951 | struct rlimit x; | |
1952 | if (resource >= RLIM_NLIMITS) | |
1953 | return -EINVAL; | |
1954 | ||
1955 | task_lock(current->group_leader); | |
1956 | x = current->signal->rlim[resource]; | |
1957 | task_unlock(current->group_leader); | |
756184b7 | 1958 | if (x.rlim_cur > 0x7FFFFFFF) |
1da177e4 | 1959 | x.rlim_cur = 0x7FFFFFFF; |
756184b7 | 1960 | if (x.rlim_max > 0x7FFFFFFF) |
1da177e4 LT |
1961 | x.rlim_max = 0x7FFFFFFF; |
1962 | return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; | |
1963 | } | |
1964 | ||
1965 | #endif | |
1966 | ||
1967 | asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim) | |
1968 | { | |
1969 | struct rlimit new_rlim, *old_rlim; | |
ec9e16ba | 1970 | unsigned long it_prof_secs; |
1da177e4 LT |
1971 | int retval; |
1972 | ||
1973 | if (resource >= RLIM_NLIMITS) | |
1974 | return -EINVAL; | |
ec9e16ba | 1975 | if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) |
1da177e4 | 1976 | return -EFAULT; |
ec9e16ba AM |
1977 | if (new_rlim.rlim_cur > new_rlim.rlim_max) |
1978 | return -EINVAL; | |
1da177e4 LT |
1979 | old_rlim = current->signal->rlim + resource; |
1980 | if ((new_rlim.rlim_max > old_rlim->rlim_max) && | |
1981 | !capable(CAP_SYS_RESOURCE)) | |
1982 | return -EPERM; | |
1983 | if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN) | |
ec9e16ba | 1984 | return -EPERM; |
1da177e4 LT |
1985 | |
1986 | retval = security_task_setrlimit(resource, &new_rlim); | |
1987 | if (retval) | |
1988 | return retval; | |
1989 | ||
9926e4c7 TA |
1990 | if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) { |
1991 | /* | |
1992 | * The caller is asking for an immediate RLIMIT_CPU | |
1993 | * expiry. But we use the zero value to mean "it was | |
1994 | * never set". So let's cheat and make it one second | |
1995 | * instead | |
1996 | */ | |
1997 | new_rlim.rlim_cur = 1; | |
1998 | } | |
1999 | ||
1da177e4 LT |
2000 | task_lock(current->group_leader); |
2001 | *old_rlim = new_rlim; | |
2002 | task_unlock(current->group_leader); | |
2003 | ||
ec9e16ba AM |
2004 | if (resource != RLIMIT_CPU) |
2005 | goto out; | |
d3561f78 AM |
2006 | |
2007 | /* | |
2008 | * RLIMIT_CPU handling. Note that the kernel fails to return an error | |
2009 | * code if it rejected the user's attempt to set RLIMIT_CPU. This is a | |
2010 | * very long-standing error, and fixing it now risks breakage of | |
2011 | * applications, so we live with it | |
2012 | */ | |
ec9e16ba AM |
2013 | if (new_rlim.rlim_cur == RLIM_INFINITY) |
2014 | goto out; | |
2015 | ||
2016 | it_prof_secs = cputime_to_secs(current->signal->it_prof_expires); | |
2017 | if (it_prof_secs == 0 || new_rlim.rlim_cur <= it_prof_secs) { | |
e0661111 AM |
2018 | unsigned long rlim_cur = new_rlim.rlim_cur; |
2019 | cputime_t cputime; | |
ec9e16ba | 2020 | |
e0661111 | 2021 | cputime = secs_to_cputime(rlim_cur); |
1da177e4 LT |
2022 | read_lock(&tasklist_lock); |
2023 | spin_lock_irq(¤t->sighand->siglock); | |
ec9e16ba | 2024 | set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL); |
1da177e4 LT |
2025 | spin_unlock_irq(¤t->sighand->siglock); |
2026 | read_unlock(&tasklist_lock); | |
2027 | } | |
ec9e16ba | 2028 | out: |
1da177e4 LT |
2029 | return 0; |
2030 | } | |
2031 | ||
2032 | /* | |
2033 | * It would make sense to put struct rusage in the task_struct, | |
2034 | * except that would make the task_struct be *really big*. After | |
2035 | * task_struct gets moved into malloc'ed memory, it would | |
2036 | * make sense to do this. It will make moving the rest of the information | |
2037 | * a lot simpler! (Which we're not doing right now because we're not | |
2038 | * measuring them yet). | |
2039 | * | |
1da177e4 LT |
2040 | * When sampling multiple threads for RUSAGE_SELF, under SMP we might have |
2041 | * races with threads incrementing their own counters. But since word | |
2042 | * reads are atomic, we either get new values or old values and we don't | |
2043 | * care which for the sums. We always take the siglock to protect reading | |
2044 | * the c* fields from p->signal from races with exit.c updating those | |
2045 | * fields when reaping, so a sample either gets all the additions of a | |
2046 | * given child after it's reaped, or none so this sample is before reaping. | |
2dd0ebcd | 2047 | * |
de047c1b RT |
2048 | * Locking: |
2049 | * We need to take the siglock for CHILDEREN, SELF and BOTH | |
2050 | * for the cases current multithreaded, non-current single threaded | |
2051 | * non-current multithreaded. Thread traversal is now safe with | |
2052 | * the siglock held. | |
2053 | * Strictly speaking, we donot need to take the siglock if we are current and | |
2054 | * single threaded, as no one else can take our signal_struct away, no one | |
2055 | * else can reap the children to update signal->c* counters, and no one else | |
2056 | * can race with the signal-> fields. If we do not take any lock, the | |
2057 | * signal-> fields could be read out of order while another thread was just | |
2058 | * exiting. So we should place a read memory barrier when we avoid the lock. | |
2059 | * On the writer side, write memory barrier is implied in __exit_signal | |
2060 | * as __exit_signal releases the siglock spinlock after updating the signal-> | |
2061 | * fields. But we don't do this yet to keep things simple. | |
2dd0ebcd | 2062 | * |
1da177e4 LT |
2063 | */ |
2064 | ||
2065 | static void k_getrusage(struct task_struct *p, int who, struct rusage *r) | |
2066 | { | |
2067 | struct task_struct *t; | |
2068 | unsigned long flags; | |
2069 | cputime_t utime, stime; | |
2070 | ||
2071 | memset((char *) r, 0, sizeof *r); | |
2dd0ebcd | 2072 | utime = stime = cputime_zero; |
1da177e4 | 2073 | |
de047c1b RT |
2074 | rcu_read_lock(); |
2075 | if (!lock_task_sighand(p, &flags)) { | |
2076 | rcu_read_unlock(); | |
2077 | return; | |
2078 | } | |
0f59cc4a | 2079 | |
1da177e4 | 2080 | switch (who) { |
0f59cc4a | 2081 | case RUSAGE_BOTH: |
1da177e4 | 2082 | case RUSAGE_CHILDREN: |
1da177e4 LT |
2083 | utime = p->signal->cutime; |
2084 | stime = p->signal->cstime; | |
2085 | r->ru_nvcsw = p->signal->cnvcsw; | |
2086 | r->ru_nivcsw = p->signal->cnivcsw; | |
2087 | r->ru_minflt = p->signal->cmin_flt; | |
2088 | r->ru_majflt = p->signal->cmaj_flt; | |
6eaeeaba ED |
2089 | r->ru_inblock = p->signal->cinblock; |
2090 | r->ru_oublock = p->signal->coublock; | |
0f59cc4a ON |
2091 | |
2092 | if (who == RUSAGE_CHILDREN) | |
2093 | break; | |
2094 | ||
1da177e4 | 2095 | case RUSAGE_SELF: |
1da177e4 LT |
2096 | utime = cputime_add(utime, p->signal->utime); |
2097 | stime = cputime_add(stime, p->signal->stime); | |
2098 | r->ru_nvcsw += p->signal->nvcsw; | |
2099 | r->ru_nivcsw += p->signal->nivcsw; | |
2100 | r->ru_minflt += p->signal->min_flt; | |
2101 | r->ru_majflt += p->signal->maj_flt; | |
6eaeeaba ED |
2102 | r->ru_inblock += p->signal->inblock; |
2103 | r->ru_oublock += p->signal->oublock; | |
1da177e4 LT |
2104 | t = p; |
2105 | do { | |
2106 | utime = cputime_add(utime, t->utime); | |
2107 | stime = cputime_add(stime, t->stime); | |
2108 | r->ru_nvcsw += t->nvcsw; | |
2109 | r->ru_nivcsw += t->nivcsw; | |
2110 | r->ru_minflt += t->min_flt; | |
2111 | r->ru_majflt += t->maj_flt; | |
6eaeeaba ED |
2112 | r->ru_inblock += task_io_get_inblock(t); |
2113 | r->ru_oublock += task_io_get_oublock(t); | |
1da177e4 LT |
2114 | t = next_thread(t); |
2115 | } while (t != p); | |
1da177e4 | 2116 | break; |
0f59cc4a | 2117 | |
1da177e4 LT |
2118 | default: |
2119 | BUG(); | |
2120 | } | |
0f59cc4a | 2121 | |
de047c1b RT |
2122 | unlock_task_sighand(p, &flags); |
2123 | rcu_read_unlock(); | |
2124 | ||
0f59cc4a ON |
2125 | cputime_to_timeval(utime, &r->ru_utime); |
2126 | cputime_to_timeval(stime, &r->ru_stime); | |
1da177e4 LT |
2127 | } |
2128 | ||
2129 | int getrusage(struct task_struct *p, int who, struct rusage __user *ru) | |
2130 | { | |
2131 | struct rusage r; | |
1da177e4 | 2132 | k_getrusage(p, who, &r); |
1da177e4 LT |
2133 | return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; |
2134 | } | |
2135 | ||
2136 | asmlinkage long sys_getrusage(int who, struct rusage __user *ru) | |
2137 | { | |
2138 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN) | |
2139 | return -EINVAL; | |
2140 | return getrusage(current, who, ru); | |
2141 | } | |
2142 | ||
2143 | asmlinkage long sys_umask(int mask) | |
2144 | { | |
2145 | mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); | |
2146 | return mask; | |
2147 | } | |
2148 | ||
2149 | asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, | |
2150 | unsigned long arg4, unsigned long arg5) | |
2151 | { | |
2152 | long error; | |
1da177e4 LT |
2153 | |
2154 | error = security_task_prctl(option, arg2, arg3, arg4, arg5); | |
2155 | if (error) | |
2156 | return error; | |
2157 | ||
2158 | switch (option) { | |
2159 | case PR_SET_PDEATHSIG: | |
0730ded5 | 2160 | if (!valid_signal(arg2)) { |
1da177e4 LT |
2161 | error = -EINVAL; |
2162 | break; | |
2163 | } | |
0730ded5 | 2164 | current->pdeath_signal = arg2; |
1da177e4 LT |
2165 | break; |
2166 | case PR_GET_PDEATHSIG: | |
2167 | error = put_user(current->pdeath_signal, (int __user *)arg2); | |
2168 | break; | |
2169 | case PR_GET_DUMPABLE: | |
2030c0fd | 2170 | error = current->mm->dumpable; |
1da177e4 LT |
2171 | break; |
2172 | case PR_SET_DUMPABLE: | |
abf75a50 | 2173 | if (arg2 < 0 || arg2 > 1) { |
1da177e4 LT |
2174 | error = -EINVAL; |
2175 | break; | |
2176 | } | |
2177 | current->mm->dumpable = arg2; | |
2178 | break; | |
2179 | ||
2180 | case PR_SET_UNALIGN: | |
2181 | error = SET_UNALIGN_CTL(current, arg2); | |
2182 | break; | |
2183 | case PR_GET_UNALIGN: | |
2184 | error = GET_UNALIGN_CTL(current, arg2); | |
2185 | break; | |
2186 | case PR_SET_FPEMU: | |
2187 | error = SET_FPEMU_CTL(current, arg2); | |
2188 | break; | |
2189 | case PR_GET_FPEMU: | |
2190 | error = GET_FPEMU_CTL(current, arg2); | |
2191 | break; | |
2192 | case PR_SET_FPEXC: | |
2193 | error = SET_FPEXC_CTL(current, arg2); | |
2194 | break; | |
2195 | case PR_GET_FPEXC: | |
2196 | error = GET_FPEXC_CTL(current, arg2); | |
2197 | break; | |
2198 | case PR_GET_TIMING: | |
2199 | error = PR_TIMING_STATISTICAL; | |
2200 | break; | |
2201 | case PR_SET_TIMING: | |
2202 | if (arg2 == PR_TIMING_STATISTICAL) | |
2203 | error = 0; | |
2204 | else | |
2205 | error = -EINVAL; | |
2206 | break; | |
2207 | ||
2208 | case PR_GET_KEEPCAPS: | |
2209 | if (current->keep_capabilities) | |
2210 | error = 1; | |
2211 | break; | |
2212 | case PR_SET_KEEPCAPS: | |
2213 | if (arg2 != 0 && arg2 != 1) { | |
2214 | error = -EINVAL; | |
2215 | break; | |
2216 | } | |
2217 | current->keep_capabilities = arg2; | |
2218 | break; | |
2219 | case PR_SET_NAME: { | |
2220 | struct task_struct *me = current; | |
2221 | unsigned char ncomm[sizeof(me->comm)]; | |
2222 | ||
2223 | ncomm[sizeof(me->comm)-1] = 0; | |
2224 | if (strncpy_from_user(ncomm, (char __user *)arg2, | |
2225 | sizeof(me->comm)-1) < 0) | |
2226 | return -EFAULT; | |
2227 | set_task_comm(me, ncomm); | |
2228 | return 0; | |
2229 | } | |
2230 | case PR_GET_NAME: { | |
2231 | struct task_struct *me = current; | |
2232 | unsigned char tcomm[sizeof(me->comm)]; | |
2233 | ||
2234 | get_task_comm(tcomm, me); | |
2235 | if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm))) | |
2236 | return -EFAULT; | |
2237 | return 0; | |
2238 | } | |
651d765d AB |
2239 | case PR_GET_ENDIAN: |
2240 | error = GET_ENDIAN(current, arg2); | |
2241 | break; | |
2242 | case PR_SET_ENDIAN: | |
2243 | error = SET_ENDIAN(current, arg2); | |
2244 | break; | |
2245 | ||
1d9d02fe AA |
2246 | case PR_GET_SECCOMP: |
2247 | error = prctl_get_seccomp(); | |
2248 | break; | |
2249 | case PR_SET_SECCOMP: | |
2250 | error = prctl_set_seccomp(arg2); | |
2251 | break; | |
2252 | ||
1da177e4 LT |
2253 | default: |
2254 | error = -EINVAL; | |
2255 | break; | |
2256 | } | |
2257 | return error; | |
2258 | } | |
3cfc348b AK |
2259 | |
2260 | asmlinkage long sys_getcpu(unsigned __user *cpup, unsigned __user *nodep, | |
2261 | struct getcpu_cache __user *cache) | |
2262 | { | |
2263 | int err = 0; | |
2264 | int cpu = raw_smp_processor_id(); | |
2265 | if (cpup) | |
2266 | err |= put_user(cpu, cpup); | |
2267 | if (nodep) | |
2268 | err |= put_user(cpu_to_node(cpu), nodep); | |
2269 | if (cache) { | |
2270 | /* | |
2271 | * The cache is not needed for this implementation, | |
2272 | * but make sure user programs pass something | |
2273 | * valid. vsyscall implementations can instead make | |
2274 | * good use of the cache. Only use t0 and t1 because | |
2275 | * these are available in both 32bit and 64bit ABI (no | |
2276 | * need for a compat_getcpu). 32bit has enough | |
2277 | * padding | |
2278 | */ | |
2279 | unsigned long t0, t1; | |
34596dc9 AK |
2280 | get_user(t0, &cache->blob[0]); |
2281 | get_user(t1, &cache->blob[1]); | |
3cfc348b AK |
2282 | t0++; |
2283 | t1++; | |
34596dc9 AK |
2284 | put_user(t0, &cache->blob[0]); |
2285 | put_user(t1, &cache->blob[1]); | |
3cfc348b AK |
2286 | } |
2287 | return err ? -EFAULT : 0; | |
2288 | } | |
10a0a8d4 JF |
2289 | |
2290 | char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; | |
2291 | ||
2292 | static void argv_cleanup(char **argv, char **envp) | |
2293 | { | |
2294 | argv_free(argv); | |
2295 | } | |
2296 | ||
2297 | /** | |
2298 | * orderly_poweroff - Trigger an orderly system poweroff | |
2299 | * @force: force poweroff if command execution fails | |
2300 | * | |
2301 | * This may be called from any context to trigger a system shutdown. | |
2302 | * If the orderly shutdown fails, it will force an immediate shutdown. | |
2303 | */ | |
2304 | int orderly_poweroff(bool force) | |
2305 | { | |
2306 | int argc; | |
2307 | char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc); | |
2308 | static char *envp[] = { | |
2309 | "HOME=/", | |
2310 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin", | |
2311 | NULL | |
2312 | }; | |
2313 | int ret = -ENOMEM; | |
2314 | struct subprocess_info *info; | |
2315 | ||
2316 | if (argv == NULL) { | |
2317 | printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", | |
2318 | __func__, poweroff_cmd); | |
2319 | goto out; | |
2320 | } | |
2321 | ||
2322 | info = call_usermodehelper_setup(argv[0], argv, envp); | |
2323 | if (info == NULL) { | |
2324 | argv_free(argv); | |
2325 | goto out; | |
2326 | } | |
2327 | ||
2328 | call_usermodehelper_setcleanup(info, argv_cleanup); | |
2329 | ||
2330 | ret = call_usermodehelper_exec(info, -1); | |
2331 | ||
2332 | out: | |
2333 | if (ret && force) { | |
2334 | printk(KERN_WARNING "Failed to start orderly shutdown: " | |
2335 | "forcing the issue\n"); | |
2336 | ||
2337 | /* I guess this should try to kick off some daemon to | |
2338 | sync and poweroff asap. Or not even bother syncing | |
2339 | if we're doing an emergency shutdown? */ | |
2340 | emergency_sync(); | |
2341 | kernel_power_off(); | |
2342 | } | |
2343 | ||
2344 | return ret; | |
2345 | } | |
2346 | EXPORT_SYMBOL_GPL(orderly_poweroff); |